1. Field of the Invention
The invention relates to the obtainment of headliners for the interior of automobiles, specifically, edged headliners of the type having a lined side.
2. Description of the Related Art
Many processes of obtaining lined stratified products are currently known, and are constituted of:                a stratified support (made up of several layers, together forming the support); and        a lining applied on the visible side of the support, which lining also covers some or all of the edges of said support.        
The support can also be obtained in a mold by means of applying heat and pressure on an assembly of layers or sheets, such that said layers are adhered to one another and adopt a configuration predetermined by the contact surfaces of the press. In the same press or in a subsequent phase, the support is trimmed, for example, to obtain the desired outline of the product and/or to arrange openings in the product. In a subsequent phase, a lining layer is applied on a visible surface or side (that corresponding to the portion seen by the user) of the support and on (at least some of) the trimmed edges of the support. The main reason for applying the lining in a phase subsequent to the support formation phase is that the lining must also cover the trimmed edges, or at least some of them; for that reason, the lining should not be trimmed together with the support.
An example of a process of this type is the process of obtaining a roof headliner for automotive vehicles. FIG. 1 schematically shows the different layers which can constitute a roof headliner for an automobile:
In the first place, there is a support 10 formed by the following layers:                a non-fabric lining 11, for example, of paper, of the non-visible side of the product;        a first reinforcement layer 12;        a first thermosetting resin layer 13 serving to join the first reinforcement layer to a central layer 14;        the central layer 14, which can be constituted of a polyurethane foam; said layer can have a semi-rigid consistency;        a second thermosetting resin layer 15 intended for joining the central layer 14 to a second reinforcement layer 16;        the second reinforcement layer 16; and        a layer of light non-fabric material 17 (serving to prevent the support from sticking to the mold in the support pressing phase).        
In the second place, joined to the layer of light non-fabric material 17, there is a lining 20 of the visible surface or side of the product (i.e., it is a lining seen by the end user) and which is normally joined to the support 10 by means of an adhesive (not shown in the figure). Many times, said lining must cover not only the main side of the support, but also different edges of the support, arranged by means of a support trimming process, this for the purpose of obtaining an end product with a better finish.
Currently, according to a standard method, the obtainment of roof headliners with edging of the lining (i.e., with the application of the lining on the edges of the support) is carried out in at least two separate pressing phases, by means of the use of two presses: one for obtaining the support and another one for applying the lining.
In the first phase, corresponding to obtaining the support, the different sheets or layers which will constitute the support are introduced in a press, one on top of the other. Then, pressure and heat are applied for the purpose of, on one hand, joining the layers (by means of polymerization of the thermosetting resins—13, 15—), and, on the other hand, giving the desired shape (curvatures, etc.) to the support. The support is also trimmed, i.e., portions of the material are eliminated for the purpose of establishing the desired outline of the support, through openings (for example, an opening corresponding to the sunroof window of the vehicle), etc. This trimming of the support can be carried out in the same press, as an integral part of the support obtainment phase, or separately, in a subsequent trimming phase carried out in another machine. As the result of the trimming and of the corresponding elimination of the portion of the laminar material, trimmed edges are formed, at least some of which must be lined with the same lining as the main visible side of the support.
In the second phase, an adhesive is applied (usually, an adhesive activated by means of pressure) on the layer of light non-fabric material of the support obtained as a result of the process described above. The support is placed in a second press, together with the visible side lining, and by means of applying pressure, the support is lined; the lining is adhered to the support by means of the adhesive applied.
The dimensions of the visible side lining somewhat exceed (in the areas which will be edged) those of the support, such that in a subsequent operation, the edging can be carried out by folding the surplus portions of the visible side lining, encircling the support.
This process is schematically shown in FIGS. 2A–2C:
In FIG. 2A, it can be observed how several layers, which will constitute a support 10, are introduced in a first press 50. The support is formed by means of applying pressure and heat. Furthermore, in the first press 50, peripheral portions of the support are also eliminated, such that edges 10a, 10b, which can be observed in FIG. 2B, are formed. In said FIG. 2B, It can be observed how the support 10 obtained in the first press 50, and with its edges 10a and 10b trimmed, has, been introduced in a second press 60, together with a lining layer 20, the ends 20a and 20b of which project with regard to the upper surface of the support. An adhesive (not shown) has previously been applied on the surface of the support 10 to which the lining 20 is to be adhered. In the second press, by applying pressure and heat, the lining 20 is adhered to the upper surface of the support, with the ends 20a and 20b of the lining free. The possibility also exists to carry out, in the second press, trimmings of the lining, for example, so that its ends or outline have the desired configuration and/or to eliminate the material corresponding to, for example, a sunroof window (in which case the trimmed portion of the lining must be less than the surface of the window, for the purpose of allowing for the edging of the visible edges of the support delimiting the window).
Then in a subsequent step, adhesive is applied on the edges 10a, 10b of the support (and/or on the free ends 20a, 20b of the lining), and said edges are covered with the surplus free ends 20a, 20b of the lining (the adhesive is usually applied on the surpluses of the lining). FIG. 2C schematically shows how the lining 20 covers the visible side of the support 10 and how the free ends 20a, 20b of the lining cover the trimmed edges of the support.
In theory, the process described requires the use of two different presses:
i) a first press for obtaining the support by means of applying pressure and heat to an assembly of layers constituting the support; optionally, the trimming of the support can also be carried out in this first press for the purpose of defining the outline of the support and possible openings (for example, for a sunroof window), with the edges which subsequently must be lined: alternatively, the support can be trimmed in a subsequent phase; and
ii) a second press in which the lining is applied on the support; optionally, possible trimmings of the lining layer can also be carried out in this second press (for example, to form the opening corresponding to a sunroof window).
With this process, it is necessary to use two presses since, if the lining is joined to the support in the first press, in the same process in which pressure and heat are applied for joining the different layers constituting the support, then when “trimming” the support, the lining layer is also trimmed, whereby there are no surplus free ends of the lining which can serve to cover the edges formed upon trimming the support, i.e., there is no surplus portion of the lining which can be used for lining said edges.
Therefore, in the standard process described, it is necessary to use a first press for shaping the support, which is then trimmed, to then pass to a second press in which the lining is applied.
To reduce expenses, it would be desirable to be able to carry out the entire process in a single press.
On the other hand, the standard process, based on the use of two presses, entails a large number of operations and usually requires several operators, for example: one operator for applying the adhesive to areas localized as the deep-drawings for the handles, sunshades etc., members requiring a large amount of adhesive so that the lining is completely adhered; another operator for applying adhesive to the entire surface of the support which must be lined; another operator for introducing the lining in the second press; another operator for positioning the support in the second press; and another operator for withdrawing the formed headliner from the second press.
U.S. Pat. No. 4,986,865 discloses a substantially known system according to that described above.
A manner of enabling the obtainment of the stratified product in a single press could be by introducing, between the layers (11–17) which will constitute the support 10 and the portions of the lining layer 20 which will constitute the surplus free ends (20a, 20b), once the support is trimmed, sheets of a material—for example, Teflon®—preventing said portions of the lining layer 20 from adhering to the support. In this manner, once the assembly integrated by support 10 and lining 20 has been obtained, the free ends (20a, 20b) of the lining are not joined/adhered to the support; then the support can be cut, and then said free ends of the lining can be folded over the trimmed ends. However, this manner of proceeding, namely, the use of Teflon® sheets or the like for preventing adhesion between the support 10 and lining 20 in certain areas (those which must be cut for the subsequent edging of the trimmed edges) can be laborious (for example, since it requires the step of introducing the Teflon® sheets), and the Teflon® sheets (or the like) can leave marks in the lining (as a result of the assembly pressing process), something which can negatively affect the final appearance of the obtained product.